Airborne water vapor differential absorption lidar

Water vapor is the most important greenhouse gas, much more effective than CO₂. It governs the atmospheric water cycle and is a key component in atmospheric chemistry. The frequent occurrence of phase transitions from vapor to liquid water or ice crystals further enhances the importance of atmospheric humidity. Cloud formation and the various forms of precipitation certainly belong to the most important weather phenomena. The strong temperature dependence of the saturation vapor pressure in combination with vertical transport processes causes a large variability of the atmospheric humidity, which exists on practically all scales from turbulence to global distribution.